In order to carry out a matrix-assisted chondrocyte transplantation (MACT), it is necessary to be able to provide quantitative information concerning the identity and purity of the cartilage tissue used and of the cartilage cells (chondrocytes) used that are to enter the implants or matrices intended for implantation.
Up to now, the identity of the cartilage tissue used has been detected via the site of removal. However, this anatomical procedure lacks documentation verifying correct removal and does not allow a quantification of the removed tissue material with regard to purity in relation to bone and connective tissue.
In the case of a piece of cartilage tissue removed from a human or animal knee joint, it is, for example, not possible to rule out a contamination with connective tissue, such as synovia for example, and/or subchondral bone. Moreover, the identity of the cartilage tissue is open to question in cases in which the nature of the biopsy does not allow an unambiguous anatomical assignment.
In principle, the identity and the purity of cartilage biopsies can be examined immunohistologically. Besides problems of practical implementation under cleanroom conditions, immunohistological examinations have, however, the disadvantage that invariably only small segments of the prepared cartilage are assessable, since histological sections typically have a thickness of <10 μm. A comprehensive detection of identity and purity that includes the entire preparation is therefore not possible.